VCAM-1-targeted core/shell nanoparticles for selective adhesion and delivery to endothelial cells with lipopolysaccharide-induced inflammation under shear flow and cellular magnetic resonance imaging in vitro

Abstract

Multifunctional nanomaterials with unique magnetic and luminescent properties have broad potential in biological applications. Because of the overexpression of vascular cell adhesion molecule-1 (VCAM-1) receptors in inflammatory endothelial cells as compared with normal endothelial cells, an anti-VCAM-1 monoclonal antibody can be used as a targeting ligand. Herein we describe the development of multifunctional core-shell Fe 3 O 4 @SiO 2 nanoparticles with the ability to target inflammatory endothelial cells via VCAM-1, magnetism, and fluorescence imaging, with efficient magnetic resonance imaging contrast characteristics. Superparamagnetic iron oxide and fluorescein isothiocyanate (FITC) were loaded successfully inside the nanoparticle core and the silica shell, respectively, creating VCAM-1-targeted Fe 3 O 4 @ SiO 2 (FITC) nanoparticles that were characterized by scanning electron microscopy, transmission electron microscopy, fluorescence spectrometry, zeta potential assay, and fluorescence microscopy. The VCAM-1-targeted Fe 3 O 4 @SiO 2 (FITC) nanoparticles typically had a diameter of 355 ± 37 nm, showed superparamagnetic behavior at room temperature, and cumulative and targeted adhesion to an inflammatory subline of human umbilical vein endothelial cells (HUVEC-CS) activated by lipopolysaccharide. Further, our data show that adhesion of VCAM-1-targeted Fe 3 O 4 @SiO 2 (FITC) nanoparticles to inflammatory HUVEC-CS depended on both shear stress and duration of exposure to stress. Analysis of internalization into HUVEC-CS showed that the efficiency of delivery of VCAM-1-targeted Fe 3 O 4 @SiO 2 (FITC) nanoparticles was also significantly greater than that of nontargeted Fe 3 O 4 @SiO 2 (FITC)-NH 2 nanoparticles. Magnetic resonance images showed that the superparamagnetic iron oxide cores of the VCAM-1-targeted Fe 3 O 4 @SiO 2 (FITC) nanoparticles could also act as a contrast agent for magnetic resonance imaging. Taken together, the cumulative adhesion and uptake potential of these VCAM-1-targeted Fe 3 O 4 @SiO 2 (FITC) nanoparticles targeted to inflammatory endothelial cells could be used in the transfer of therapeutic drugs/genes into these cells or for diagnosis of vascular disease at the molecular and cellular levels in the future.

Dense nanoparticles exhibit enhanced vascular wall targeting over neutrally buoyant nanoparticles in human blood flow

“…The 500 nm particle size used in this study is relevant for drug delivery in that spheres with diameters on the order of 200 nm have typically been proposed for use as VTCs (e.g. 250 nm in [64]; 190 nm in [65]; 330 nm in [66]), and we have shown in several publications that 200 nm and 500 nm spheres exhibit similar margination and binding dynamics under human blood flow conditions. [4,38] Moreover, VTCs in the 200 -500 nm have previously been evaluated in vivo in mice with no significant adverse effects reported.…”

Multifunctional Core/Shell Nanoparticles Cross-linked Polyetherimide-folic Acid as Efficient Notch-1 siRNA Carrier for Targeted Killing of Breast Cancer

“…FITC-APS conjugates were prepared in advance via an addition reaction between the isothiocyanate group of FITC dye and the primary amine group of APS. This synthetic process enables the co-encapsulation of Fe 3 O 4 nanoparticles and a large number of FITC dye molecules to stay together within the silica shell 4 28 29 . Using fluorescence microscopy, we confirmed that both Fe 3 O 4 @SiO 2 (FITC) and Fe 3 O 4 @SiO 2 (FITC)/PEI-FA nanoparticles were well-dispersed, and distinct fluorescence existed for the two nanoparticles ( Figure 3 ).…”

“…The results indicate that about one FA molecular chain was conjugated to one PEI molecular chain. To verify whether the PEI-FA co-polymer were coated on the surface of Fe 3 O 4 @SiO 2 (FITC) nanoparticles, fluorescence emission spectra were used and the results showed an emission peak at the wavelength of approximately 440 nm for the Fe 3 O 4 @SiO 2 (FITC)/PEI-FA nanoparticle suspension ( Figure 4B ), which is the characteristic fluorescence emission peak of FA 4 10 31 , suggesting that PEI-FA molecules were successfully coated onto the surface of Fe 3 O 4 @SiO 2 (FITC) nanoparticles. The zeta potential analysis further showed a positive surface charge of +17.5 ± 1.3 mV ( Figure 4C ) for the Fe 3 O 4 @SiO 2 (FITC)/PEI-FA nanoparticle, suggesting that the Fe 3 O 4 @SiO 2 (FITC)/PEI-FA nanoparticle could bind to the negatively charged Notch-1 shRNA through electrostatic interaction.…”

“…Fe 3 O 4 @SiO 2 (FITC) was prepared following a previously described procedure with some minor modifications 4 16 17 . Briefly, 2 mg of FITC was mixed with 125 μl of APS in 1 mL of anhydrous ethanol in the dark and allowed to react at room temperature for 24 h. The resulting mixture of FITC-APS conjugates in solution was then stored at 4°C.…”

“…Silica is one of the exceptional coating materials for encapsulating magnetic nanoparticles because of its good biocompatibility, excellent physicochemical stability, and its ease of surface multi-functionalization. In general, silica coating can be achieved by the Stöber process or the reverse (water-in-oil) microemulsion method 3 4 5 6 . These silica-coated fluorescent magnetic nanoparticles have been widely used to develop biomedical platforms for simultaneous imaging, diagnosis, and therapy.…”